I would like to share with you guys this awesome guide just recently made by a reddit user called Undoer (link to his reddit profile HERE).

Its 34 pages full of information to help new players understand what their class can and can't do, how it plays, what flavour or mechanics are unique to that class, and what roles it can perform in, and also what roles it can easily access groups in.

This is probably the most comprehensive guide for helping new players select a class. Thank you for sharing this, I'll definitely forward this to any new players I manage to coax into playing Classic WoW!